Cooling unit



March 1, 1938. c. LICHTENBERG 2,110,002

COOLING UNIT Original Filed June 14, 1955 Fig. 2.

Inventor- Chester- Lichtenberg,

His Attorneylid lid

Wil

Fe mented iii fare ll,

tuner (Chester ltichtenhcrg, Fort Wayne, llnd, assigimor to GeneralElectric Company, a corporation of New York Application time it, was,Serial at. 26,562 Renewed September 15, 193? 6 Claims.

My invention relates to cooling units for refrigerating machines.

It is an object of my invention to provide an improved and simplifiedcooling unit for refrigerating machines having a plurality of shelvesfor supporting freezing trays and the like, and having a simple andemcient arrangement for circulating liquid refrigerant through passagesin the shelves.

Further objects and advantages of my invention will become apparent asthe following .description proceeds and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming a part of this specification.

For a better understanding of my invention reference may be had to theaccompanying drawing in which Fig. 1 shows a household refrigeratorhaving a cooling unit embodying my invention; Fig. 2 is a detailperspective view of the back of the cooling unit shown in Fig. 1; andFig. 3 is a developed view showing the refrigerant circulating passagesin one of the evaporators'of the cooling unit.

Referring now'to the drawing in Fig. l, I have shown a householdrefrigerator comprising a cabinet it having a door it, and provided witha refrigerating machine'including a motor and 'cpmpressor casing if, acondenser it having refrigerant conduits i l and secured to the casingif, a float valve or receiver l5, and a cooling unit it embodying myinvention. The cooling unit is arranged within the cabinet ill and issuspended from a removable top I'll of the cabinet, which alsoconstitutes the base on which is mounted the motor and compressor casingit. During the operation of the refrigerating machine gaseousrefrigerant is compressed by the compressor within the casing if and isdischarged into the conduit M of the condenser where it is cooled by thecirculation of air around the condenser, and is thereby liquefied. Theliquid refrigerant flows from the condenser to the receiver or floatvalve chamber l5 and when a predetermined amount of liquid has cooled,at float within the chamber iii rises and refrigerant flows through aconduit it to the cooling unit it. The liquid refrigerant is circulatedthrough the cooling unit and absorbs heat from the cabinet wand fromfreezing trays or other articles placed within the cooling unit. Thisabsorption of heat vaporizes the liquid refrigerant which collects in anupper header iii of the cooling unit and is withdrawn from the headerthrough a conduit 20 and returned to the compressor.

" passages is thus of B shaped cross section.

(Ulla (rig-112 5) The cooling unit iii is constructed of sheet metal andcomprises an upper evaporator and a lower evaporator of substantiallythe same construction, each evaporator being formed of sheet metal andhaving a header and a plurality of depending refrigerant circulatingpassages formed between the metal sheets and providing circulation ofrefrigerant through the freezing tray supports or shelves. Thisconstruction is clearly shown in Fig. .2 where I have shown an upperevaporator 2i and a lowerhevaporator 22 each formed from two sheets ofmetal secured to gether face to face and provided with indentationsforming a header and a plurality of refrigerant circulating'passages.The upper evaporator 2i and the lower evaporator 22 are of substantiallythe same construction and the same numerals have been applied tocorresponding parts of the two evaporators. Fig. 3, which is"a developedview of the upper evaporator ff, shows the arrangement of the header itand the circulating conduits or passages. The outer sheet 26 is shownplaced over the inner sheet ft with the edges ftl of the inner sheetfolded over the edges of the sheet f t. The header it is formed bycomplementary indentations in the sheets ft and it near one end of thesheets. A plurality of U shaped passages or conduits ft communicatingwith a manifold fl through a plurality: of ducts 2t and a liquid inletpassage 29a are formed by indentations in the outer sheet td; and asinuous passage or conduit 29 is formed. by indentations partly in thesheet 2t and partly in the sheet if, the portions of the passage in thesheet fit being shown by dotted lines. The passage 29 communicates atone end with the liquid passage the, and at the other end with themanifold fl. The sheets 2%? and M are hermetically sealed togetheraround their edges and between the indentations by welding or in anyother suitable manner, and the sheets are then bent into the form shownin Fig. 2, a flange 3% on the sheet 23 being bent at right angles to thesheet and being secured by welding to the side wall of theevaporator.The portion of the evaporator containing the refrigerant circulatingfreezing chamber is formed between upper and lower shelves iii and fit,and a wall 33 is welded 355 formed on the evaporator fl above the headerit and on the'wall respectively are provided in order to secure thecooling unit to the top wall of a refrigerator cabinet. The lowerevaporator 22 is of substantially the same construction as theevaporator 2 I, except that in place of a flange corresponding to theflange 34, the evaporator 22 is provided with a plurality of lugs 36extending vertically from the wall of header l9 thereof. The lugs arewelded or otherwise secured to the evaporator 2| between the passages26, and the wall 33 of the evaporator 22 is provided with an offsetvertical extension 31 whereby it is secured by welding or in any othersuitable manner to the evaporator 2|.

The construction of the evaporators 2| and 22 and the arrangement of thecirculating passages is not my invention, but is the invention ofLeonard W. Atchison, and is shown and described in his co-pendingapplication Serial No. 7,683, filed February 23, 1935, and assigned tothe General Electric Company assignee of my present invention. I do not,therefore, herein claim anything claimed in the said Atchisonapplication which is to be regarded as prior art with respect'to thepresent application, my invention relating to an improved method forconstructing a cooling unit comprising a plurality of evaporators.

Each of the evaporators 2| and 22 is provided with guards 38 which'prevent freezing trays or other articles placed on the shelves frombeing pushed too far to the rear of the cooling unit. After theevaporators 2| and 22 have been secured together in the mannerdescribed, the headers |9 are connected by an equalizer tube or conduit39 of relatively large diameter. This equalizer tube provides a passagewhereby liquid and gaseous refrigerant may flow from the lower header tothe upper header; it is maintained filled with liquid refrigerant duringnormal operation of the cooling unit.

During the operation of the refrigerating machine shown in Fig. 1,liquid refrigerant is admitted to the cooling unit from the float valvechamber l5, conduit i8, and connections 40 and 4|, the latter beingconnected to evaporators 2| and 22 respectively. The admission of liquidrefrigerant to the cooling unit in this manner produces a circulation ofrefrigerant through freezing shelves 3| and 32 of evaporators 2| and 22.The refrigerant is vaporize'd upon the absorption of heat from the airsurrounding the cooling unit and articles placed within the unit and therefrigerant vapor collects in the headers l9. Some gaseous refrigerantmay be trapped in the lower header l9 above the lower opening of thetube 39 and as more vapor is formed it will rise to the top of the lowerheader l9 and depress the liquid level until the vapor bubbles upthrough the liquid refrigerant in the tube 39 to the upper header IS..The gaseous refrigerant is withdrawn from the cooling unit through asuction connection 20. The normal liquid level within the header I! ofthe evaporator 2| is maintained so that the upper end 43 of theconnection tube 39 will be partially below the normal liquid level whichis indicated at 44. The tube 39 is thereby maintained filled with liquidrefrigerantduring normal operation of the cooling unit.

It will be apparent from the foregoing that I have provided a coolingunit having a large number of freezing shelves providing eflicientcirculation of refrigerant and hich is simple to construct andeconomical to manufacture.

While I have shown my invention in connection with a cooling unit for ahousehold refrigerator variations in the structure thereof will readilybe apparent to those skilled in the art. I do not, therefore, desire myinvention to be limited to the particular construction shown anddescribed, and I intend in the appended claims to cover allmodifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is: v

1. A cooling unit for refrigerating machines comprising an upper headerand a lower header, a plurality of liquid refrigerant circulatingconduits communicating with said upper header and depending therefrom, aplurality of liquid refrigerant circulating conduits independent of saidfirst-mentioned conduits and communicating with said lower header anddepending therefrom, means supplying liquid refrigerant to said coolingunit for producinga circulation of refrigerant therein, means providingcommunication between said headers for removing liquid and gaseousrefrigerant from said lower header, and means for removing gaseousrefrigerant from said upper header.

2. A cooling unit for refrigerating machines comprising an upper headerand a lower header, a plurality of liquid refrigerant circulatingconduits communicating with said upper header and depending therefrom, aplurality of liquid refrigerant circulating conduits independent of saidfirst-mentioned conduits and communicating with said lower header anddepending therefrom, means supplying liquid refrigerant to said conduitsfor producing a circulation of refrigerant therein, means providingcommunication between said headers for removing liquid and gaseousrefrigerant from said lower header, and means for withdrawing gaseousrefrigerant from said upper header.

3. A cooling'fiunit for refrigerating machines comprising an upperheader and a lower header, a plurality of liquid refrigerant circulatingconduits communicating with said upper header and depending therefrom, aplurality of liquid refrigerant circulating conduits communicating withsaid lower header and depending therefrom, means supplying refrigerantto said conduits depending from said upper header for producing acirculation of refrigerant therein, means supplying refrigerant to saidconduits depending from said lower header for producing a circulation ofrefrigerant therein, means providing communication between said headersfor removing liquid and gaseous refrigerant from said lower meansincluding a plurality of conduits communicating with said upper headerfor providing a plurality of surfaces for supporting freezing trays andthe like, means including a plurality of conduits independent of saidfirst-mentioned conduits and communicating with said lower header forproviding a plurality of surfaces for supporting freezing trays and thelike, means supplying liquid refrigerant to said conduits for producinga.circulation of refrigerant therein, means providing communicationbetween said upper header and said lower header for withdrawing liquidand gaseous refrigerant from said lower header, and means forwithdrawing gaseous refrigerant from said upper header.

5. A cooling unit for refrigerating machines airopoa comprising an upperevaporator and a lower evaporator, each of said evaporators comprisingsheets of metal secured together face to face and having a header and aplurality of depending liquid refrigerant circulating conduits formedtherein and communicating with the header, each of said evaporatorsproviding a plurality of surfaces for supporting freezing trays and thelike, means supplying liquid refrigerant to said con duits for producinga circulation of refrigerant therein, means providing communicationleetween the header of said upper evaporator and the header of saidlower evaporator for withdrawing liquid and gaseous refrigerant fromsaid low- 15 er evaporator, and means for withdrawing gasa lower sheetmetal evaporator, each of said evaporators having formed therein aheader and a plurality of depending refrigerant circulating conduits,and means for supporting said lower evaporator from said upperevaporator, said means including a plurality of lugs formed in the sheetmetal at the upper end of said lower evaporator and engaging the wall ofsaid upper evaporator in a plurality of the spaces between therefrigerant conduits thereof.

CHESTER LICHTENBERG.

